饱和二氧化碳溶液中稀土铈转化膜对X70钢缓蚀性能的研究

Research on the Inhibition Performance of Rare-earth Cerium Conversion Film for X70 Pipeline Steel in Carbon Dioxide-saturated Solution

利用Ce2(SO4)3溶液在X70钢表面制得金黄色铈转化膜,通过正交试验确定最佳成膜工艺条件。采用点滴试验、失重法及极化曲线测试分析了转化膜的耐蚀性能,用金相显微镜观测了有转化膜的钢腐蚀前后的形貌。失重法及极化曲线测试结果表明:铈转化膜可明显降低X70钢的腐蚀速率,缓蚀效率达80%以上。金相显微镜测试结果表明,存在铈转化膜的X70钢腐蚀前后形貌基本不变,耐蚀性能明显提高。

Rare-earth cerium conversion film was obtained on surface of X70 pipeline steel by immersing in a solution of Ce2 （SO4）3. The optimal condition of the passivation was gained according to the results of orthogonal test. The corrosion resistance of cerium conversion film was evaluated by spot test, weight loss method and electrochemical polarization curves technique. The metallographic microscope was used to characterize the cerium conversion film after the steel corrosion. The result indicated that the rare-earth cerium conversion film＇s corrosion inhibition ability is obviously improved, and the inhibition efficiency can reach more than 80%. Metallographic microscope test result showed that the morphology of the cerium conversion coating on X70 steel remains nearly unchanged after corrosion,and the corrosion resistance has improved significantly.